In general, an ink jet printer (ink jet recording apparatus) has a construction in which an ink cartridge filled with an ink are adopted to be installed to or mounted on a cartridge case. In such a printer, the ink contained in the ink cartridge mounted on the cartridge case is supplied to a recording head main body through an ink supply needle. (See, for example, Japanese Patent Application Laid-open No. 2000-218813.)
Japanese Patent Application Laid-open No. 2000-218813 discloses an ink jet printer having a cartridge case divided into a larger compartment and a smaller compartment. The larger compartment of the ink cartridge case are provided with three projections in the periphery of respective ink supply needles in an upstanding manner, and the height of the projections is greater than that of ink supply needles. A ink cartridge has three recesses formed in the lower surface thereof for engaging with the three projections of the ink cartridges cases. Accordingly, when the ink cartridges are mounted on the ink cartridge case, it is necessary that the positions of three projections and the positions of three recesses coincide with each other. Otherwise, the ink cartridge cannot be mounted on the ink cartridge case.
Accordingly, by changing the positions in which the projections and recesses are formed or the shape of the projections and recesses per each model of printer, it is possible to ensure that an ink cartridge is mountable only to a cartridge case included in the model of printer to which the ink cartridge corresponds. As a result, it is possible to prevent the ink cartridge from being mounted by mistake on a model of printer to which the ink cartridge does not correspond to.
The countermeasures to prevent such a mis-installation of ink cartridge are often adopted also for an ink jet printer which performs high-quality color printing with a plurality of ink cartridges each corresponding to different kinds of color inks. In other words, in such a printer, when the user mounts one or more ink cartridge or cartridges on a compartment or compartments of the cartridge case corresponding to the color other than that of the ink cartridge, problems arise such that the inks of different colors are mixed in the cartridge case and the ink cartridge cannot be used. Thus, it is necessary to prevent the ink cartridge of one color from being mounted on the compartment of the cartridge case of color different from that of the ink cartridge. In some cases, ink cartridges having a same shape regardless of the kind of inks are used for such a printer. These ink cartridges are affixed with labels for distinguishing the colors thereof and constructed so that the user cannot mount an ink cartridge of one color on the compartments of ink cartridge case corresponding to a color different from that of the ink cartridge.
As the methods for distinguishing the colors of inks contained in the ink cartridges include, for example, a method to cut a predetermined projection among the plurality of projections provided in the respective surfaces of the ink cartridges, a method to change the shapes of ink cartridges per each of the colors or the positions of insert dies used when the ink cartridges are molded, and a method to attach components for distinguishing colors to the ink cartridges. However, with these methods as described above, problems arise such as one or more extra step or steps in the process for producing the cartridges are required, the mold cost is increased, and/or the number of parts are increased, thereby raising the mold and control costs.